1. Field
Various examples relate generally to telephone accessory devices and, more particularly, to a device and method for securing dual tone multi-frequency (DTMF) tones during transmission from a telephone.
2. Background
In many countries, electronic banking is done by telephone, where a customer calls the bank's automatic service number, and uses the telephone keypad to respond to recorded prompts for menu items, account numbers, private identification numbers (PINs), amounts, and so on. Such information is often transmitted in dual tone multi-frequency (DTMF) signals from the telephone to the bank server. While such transactions over the Internet are often secured using secure socket layer (SSL), but there is no corresponding security for DTMF tones from telephones. In developing countries, banks often make such telephone services available to their customers. However, such services may be vulnerable to malicious parties that tap into the telephone wires to discover or capture sensitive information, such as customer account numbers and PINs, and then use the information to transfer money out of the accounts.
Therefore, it is desirable to provide a way to secure transmissions of DTMF tones from a telephone. Possession of the encryption device can simultaneously form a second factor of authentication for the customer, further enhancing security.